Well casing



May 22, 1934 I c. B. KENNEDYE 1,959,367

v WELL CASING v Filed sept. 24, 1932 Patented May 22, 1934 UNITED STATESl PATENT OFFICE 3 Claims.

This invention relates to the art of well casing.

`In the drilling of wells, particularly oil wells,

it is the common practice to drill a certain amount of open hole. vAstring of casing is then 5 run in and cement is pumped through thecasing and out through a shoe located on the bottom of the casing insuch a manner as to force the cement in the space between the outer wallof the casing and the wall of the open hole. l This cementing anchorsthe casing and prevents water encroachment. In actual practice, thecasing is not truly centered in the hole but, due

to the fact that the well is not drilled straight or true to theVertical and the fact that the casing l when being cemented is intension, which allows,l

the casing to flex, the tendency is for the bottom of the string to layagainst one side of the hole rather than remain in the center.

One of the objects of this invention is to provide spacing means whichwill space the casing from the wall of the hole in order to provideample room on all sides of the casing for running in the cement.

Another object of the invention is to provide means which will so director bale the flow of cement as will cause it to be positioned uniformlyabout the casing, and thus prevent voids and jetting.

Another object of the invention is to provide novel means for attachinga rubber spacing member to the outside wall of a casing.

Other objects will be apparent from the following detail description,taken in connection with the accompanying drawing, in which- Fig. 1 isan elevation of a string of casing with the device of the inventionsecured in position.

Fig. 2 is a detail section on the line 2-2 of Fig. 1.

Fig. 3 is a detail plan view of a piece of the spacing member.

Fig. 4 is an elevation of a section of casing with a modified form ofattaching means.

Fig. 5 is a cross-section on the line 5-5 of Fig. 4.

A string of casing 1, as shown in Fig. 1, is adapted to be inserted inan open drill hole 2. The common practice is to set a 'l-inch (outsidediameter) casing inside of a 9%-inch hole, or an B-inch casing inside ofan 11-inch hole. It is desirable, in order to get cement distributedabout the casing, that the casing be spaced from the walls of the holeand that it be positioned as near as possible centrally o f the hole. Inorder to secure this result, I place a spiral spacing member about thecasing for a considerable distance, preferably twenty-five feet or more,above the bottom of the casing or the usual casing shoe 3.

- The spacing member comprises an /elongatedl strip of live rubber 4clamped in a metallic strip 5. The rubber strip 4 is preferably of thesection shown in Fig. 2, that is semi-cylindrical with outwardlyextending anges 6 at each side. The rnetallic strip 5 has upwardlyextending overhanging flanges 'l which clamp against the side flanges 6of the rubber strip. Y

In the embodiment illustrated in Figs. 1, 2 and 3, outwardly extendinglugs 8 are formed from the metallic strip by cutting such Vpieces awayfrom the flanges 7. In such an embodiment, the spacing member may bereadily secured to the casing by welding the lugs 8 thereto.

In the embodiment illustrated in Figs. 4 and 5, the rubber strip 4 iscut away, as shown at 9, sufficiently to receive a metallic strap 10which bears against the top of the flange '7. The strap 10 may befastened by a clamp 11 which is crimped in position. Means for jackingthe strap 10 to position and applying the clamp 11 are well known in themetal working arts and need not be described in detail.

The amount of air pressure used in forcing the cement through the casingand between the casing and the well bore is very high, and this has atendency to cause air voids and also a jetting effect, with the resultthat the casing is not entirely surrounded by cement. The use of thespacing member in spiral form has a baiiing effect upon the cement andcauses it to circulate uniformly about the wall of the casing and to beevenly distributed.

According to present practice, it is impossible to land the casingwithin feet of the bottom of the hole because, in running in the casing,the shoe hits the side walls of the open hole, causing shale and variousformations to cave and `fall into the drilled hole. With the use of thespacing member, the casing will not touch the side of the hole and willnot gouge out the wall. Since the vspacing member is round and of liverubber, it tends to compress and smooth the wall of the hole rather thanto gouge out the formation and cause it to cave. It will, therefore, beseen that the invention accomplishes its objects.

Various changes in the details of construction may be made. within thescope of the appended. claims without departing from the spirit of thisinvention.

I claimzy 1. In combination with a well casing, an eloncasing andsecured thereto, said member com? gated spacing v-member Wound spirallyabout the secure the rubber strip to the metallic strip and havingoutwardly extending lugs, said lugs being welded to the casing.

3. In combination with a well casing, an elongated spacing member woundspirally about the casing, said member comprising a strip of rubber,

having at its top a substantially semi-cylindrical Y cross-section andat its bottom outwardly extending anges, and an underlying metallicstrip having at its sides upwardly extending flanges overhanging andclamping the flanges of the rubber strip, and means for securing saidmember to the casing.

CHARLES B. KENNEDYE.`

